ABSTRACT This proposal addresses the idea that activation of sirtuin-1 (Sirt1), a deacetylase that can regulate gene expression, will increase retinal ganglion cell (RGC) survival and visual system function in glaucoma. Activation of Sirt1 is essential to caloric restriction-induced reduction of age-related morbidity and increase of lifespan. This enzyme exerts its effects on metabolism, mitochondrial function, and other cell functions largely by deacetylation of histones and other proteins. Caloric restriction-induced protection against the normal age-related loss of retinal ganglion cells by Sirt1 activation suggests that the sirtuins are highly relevant to glaucoma. Growing evidence indicates that many, though not all, of the salutary benefits of caloric restriction can be induced by feeding with resveratrol, a sirtuin activator and natural compound, that is enriched in certain foods including red wine and peanuts. Our overall hypothesis is that increased Sirt1 activation will protect against glaucomatous damage in the retina, optic nerve, and brain of mouse models of glaucoma. Our general approach will be to investigate the effect of increasing Sirt1 activation by caloric restriction or by dietary resveratrol supplementation and to identify the role of Sirt1 by the use of transgenic mice lacking SIRT1 expression in their RGCs. Specific Aims will be: 1) to determine whether Sirt1 activation will reduce RGC loss of Thy-1 gene expression and RGC death following optic nerve injury; 2) to determine the biological basis of Sirt1-mediated RGC protection by evaluating retinal lipid peroxidation, mitochondrial integrity and function, and acetylation of proteins (including histones and transcription factors) critically involved in gene regulation; and 3) to determine whether Sirt1 activation preserves the structural integrity and function of the central visual system pathway.